Revert "Fix capturing variables in optimized compilations"

tests/language/regress_26453_test.dart

-// Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-
-// The program crashed with segfault because we when we first compile foo
-// and bar we allocate all four variables (a, b, c and d) to the context.
-// When we compile foo the second time (with optimizations) we allocate
-// only c and d to the context. This happened because parser folds away
-// "${a}" and "${b}" as constant expressions when parsing bar on its own,
-// i.e. the expressions were not parsed again and thus a and b were not
-// marked as captured.
-// This caused a mismatch between a context that bar expects and that
-// the optimized version of foo produces.
-
-foo() {
-  const a = 1;
-  const b = 2;
-  var c = 3;
-  var d = 4;
-
-  bar() {
-    if ("${a}" != "1") throw "failed";
-    if ("${b}" != "2") throw "failed";
-    if ("${c}" != "3") throw "failed";
-    if ("${d}" != "4") throw "failed";
-  }
-
-  bar();
-}
-
-main() {
-  for (var i = 0; i < 50000; i++) foo();
-}